بررسی عددی تأثیر پدیده ریزش پوسته لیپیدی میکروحباب‌های عامل کنتراست فراصوت بر پاسخ فرکانسی آن‌ها

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی کارشناسی ارشد، دانشگاه تربیت دبیر شهید رجایی، تهران، ایران

2 دانشیار، دانشگاه تربیت دبیر شهید رجایی، تهران، ایران

چکیده

عوامل کنتراست فراصوت یا UCA ها، میکروحباب­هایی با یک پوسته زیست‌سازگار هستند که با تزریق در خون باعث افزایش وضوح تصویر در سونوگرافی می­شوند. ریزش لیپید در UCAها به فرآیند جداشدن لیپید از پوستة میکروحباب تحت تحریک میدان فراصوت اشاره دارد. در این مقاله، با تحلیل ابعادی نشان داده می‌شود که پدیده‌های انتشار در مقیاس‌های زمانی که یک پالس فراصوت معمولی را مشخص می‌کنند، ناچیز هستند. سپس با استفاده از نرم‌افزار متلب به حل عددی یک نوع معادله رایلی - پلیست تغییریافته که هم مکانیزم ریزش چربی و هم ویژگی­های پوسته لیپیدی را توصیف می‌کند، پرداخته شده است. بررسی نتایج نشان می­دهد که میکروحباب­ها بر اثر ریزش پوسته پس از پالس­های تحریک متوالی در نهایت به شعاع تعادلی ثابتی می­رسند و این پدیده موجب کاهش معناداری در شدت مؤلفه‌های پاسخ فرکانسی پخش شده از آن­ها می­شود.

کلیدواژه‌ها


عنوان مقاله [English]

Numerical Investigation of the Effect of Lipid Shell Shedding Phenomenon of Ultrasound Contrast Agent Microbubbles on their Frequency Response

نویسندگان [English]

  • Amirreza barkand 1
  • miralam mahdi 2
1 Master's student، Shahid Rajaee Teacher Training University
2 associate professor,، Shahid Rajaee Teacher Training University
چکیده [English]

Ultrasound contrast agents or UCAs are microbubbles with a biocompatible shell that increase the resolution of the ultrasound image when injected into the blood. Lipid shedding in UCAs refers to the process of lipid separation from the microbubble shell under ultrasound field stimulation. In this paper, it is shown by dimensional analysis that diffusion phenomena are negligible on the time scales that characterize a typical ultrasonic pulse. Then, using MATLAB software, a modified Rayleigh Plesset equation was solved numerically, which describes both the mechanism of lipid loss and the characteristics of the lipid shell. The results shows that the microbubbles eventually reach a constant equilibrium radius due to shell shedding after successive excitation pulses and this phenomenon causes a significant decrease in the intensity of the frequency response components emitted from them.

کلیدواژه‌ها [English]

  • Ultrasound Contrast Agent Microbubbles
  • Lipid Shedding
  • Bubble Dynamics
  • Frequency Response

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